bspci2e Package

This package is designed to compute atomic structures and dipole matrix elements for 1-electron and 2-electron systems, and to perform time-dependent Schrödinger equation (TDSE) calculations.

Project Structure
Installation and Library Setup
- Dependencies
- Compilation of External Libraries
Compilation of Executables
Execution Commands

Project Structure

The directory tree for the bspci2e package is organized as follows:

bspci2e/               # Main directory
├── src/               # Source code and compilation configuration
├── lib/               # Package libraries (libnag.a, libslatec.a)
├── bin/               # Binaries (executables)
└── run/               # Execution directories
    ├── he/            # Atomic structure and TDSE calculation directory
    │   ├── bin/       # Soft link to ../../bin (executables)
    │   ├── inp/       # Input files for atomic structure (h1e.inp, cfg-0.inp, cfg-1.inp, r12.inp)
    │   ├── dat/       # Atomic structure data files
    │   ├── out/       # Output files (ASCII)
    │   ├── tinp/      # TDSE input files (pulse.inp, tdse_bs.inp)
    │   ├── tdat/      # TDSE data files
    │   ├── tout/      # TDSE output files (ASCII)
    │   └── log/       # Log files

Installation and Library Setup

Dependencies

Ensure the following libraries are installed on your system:

Lapack & openBLAS:

sudo apt-get install liblapack-dev
sudo apt-get install libopenblas-dev

NetCDF Fortran Interface:
```
sudo apt-get install libnetcdff-dev
```

Compilation of External Libraries

Slatec Library

Expand the libslatec.tgs archive.

Compile the Slatec library:

gfortran -O2 -c *.f
ar cst libslatec.a *.o

Move the generated library into the ./lib directory:
```
mv libslatec.a ./lib/
```

Nag17 Library

Extract the libnag.tar.gz archive in ./lib (this should be included in the repo).
Compile and build the Nag library:
```
cd libnag/scripts
./compile
./buildlib
```
Move the generated library into the ./lib directory:
```
mv libnag.a ./lib/
```

Compilation of Executables

Navigate to the source directory:
```
cd ./src
```
Clean previous builds:
```
make clean cleanlib
```
Compile the libraries:
```
make lib
```
Generate the executables:
- For 1-electron and 2-electron atomic structure calculations:
```
make fxd_exe
```
- For TDSE calculations:
```
make tdse_exe
```
The compiled executables will be placed in the ./bin directory.

Set up symbolic links for execution:

Navigate to the run/{quantum_system}/{specific_run_folder} directory and create a symbolic link to the bin folder:

# These commands can vary depending on how many directories deep into the run folder you are executing want to execute your runs from
# The assumption is that you will run simulations from ./run/{helium_or_qdot}/{specific_run_folder}, so 2 levels deeper into ./run
# It should not matter where you run from once you create symbolic links back to ./bin and ./scr (hopefully, if the codebase isn't too flawed)
cd ./run/he/{run_name(anything)}
ln -s ../../../bin 
ln -s ../../../scr

Execution Commands

1-electron Structure and Dipole Matrix

To calculate the 1-electron structure and dipole matrix elements (h1e):

Diagonalize the h1e Hamiltonian and calculate dipole matrix elements for l = 0 to 7:
```
bin/run-h1e.scr 0 7 bin
```

2-electron Structure and Dipole Matrix

For 2-electron structure and dipole matrix elements (h2e):

Calculate 1/r_12 matrix elements for h2e with L = 0, 1, 2, 3:

bin/Rv2eb 0 > out/v2eb-L0.out
bin/Rv2eb 1 > out/v2eb-L1.out
bin/Rv2eb 2 > out/v2eb-L2.out
bin/Rv2eb 3 > out/v2eb-L3.out

Diagonalize the h2e Hamiltonian for L = 0, 1, 2, 3:

bin/Rh2eb 0 > out/h2eb-L0.out
bin/Rh2eb 1 > out/h2eb-L1.out
bin/Rh2eb 2 > out/h2eb-L2.out
bin/Rh2eb 3 > out/h2eb-L3.out

Select the 1000 lower-energy states from the h2e diagonalization:

bin/Rw2eb 0 1500 > out/w2eb-0-1500.out
bin/Rw2eb 1 1500 > out/w2eb-1-1500.out
bin/Rw2eb 2 1500 > out/w2eb-2-1500.out
bin/Rw2eb 3 1500 > out/w2eb-3-1500.out

Calculate 2-electron dipole matrix elements:

bin/Rd2eb 0 v he > out/d2eb-01-v.out
bin/Rd2eb 1 v he > out/d2eb-12-v.out
bin/Rd2eb 2 v he > out/d2eb-23-v.out

(Optional, for length gauge):

bin/Rd2eb 0 l he > out/d2eb-01-l.out
bin/Rd2eb 1 l he > out/d2eb-12-l.out

Convert dipole matrix elements to dmx files in NetCDF format:
```
bin/Rncf 0 3 v 0
```
- (Optional, if length gauge dipole matrix elements were calculated):
```
bin/Rncf 0 2 l 0
```

TDSE Calculations

To perform TDSE calculations, ensure you have the correct input files (tinp/tdse_bs.inp and tinp/field.inp):

Run the TDSE calculation:
```
bin/Rtdse_bs
```

This document provides a complete guide to setting up, compiling, and executing the bspci2e package for atomic structure and TDSE calculations.

cavebot/amo-physics